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[159.2.239.150]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-91ece95b508sm43946716d6.0.2026.11.09.06.52.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 09 Nov 2026 06:52:50 -0800 (PST) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1xQQjq-00000001RUr-0lev; Mon, 09 Nov 2026 10:52:50 -0400 Date: Mon, 9 Nov 2026 10:52:50 -0400 From: Jason Gunthorpe To: Mostafa Saleh Cc: Pranjal Shrivastava , Joerg Roedel , Will Deacon , Robin Murphy , Kevin Tian , Daniel Mentz , Samiullah Khawaja , Logan Odell , iommu@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH 0/5] iommupt: Introduce IO page table shrinker Message-ID: <20261109145250.GO663069@ziepe.ca> References: <20261001230219.818128-1-praan@google.com> <20261002150844.GC3481470@ziepe.ca> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Mon, Nov 09, 2026 at 12:34:54PM +0000, Mostafa Saleh wrote: > I believe there is a value in supporting other users beyond IOMMUFD/VFIO > (eg. DMA domains) or even outside of iommupt, I haven't investigated this, > but it's worth looking into either integrating the "iommupt clean(gap)" > idea in the IOVA allocator or more generally rely on refcounting + > shrinker (or other method). The main point is to avoid the refcounting because that is going to be a perf negative for everyone.. I think most people should be able to do a clean call, and if it is routed as a generic domain function that would be fine too Jason